Duplicating machine



Nov. 8, 1932. A. TUPPER DUPLICATING MACHINE Filed Feb. 26, 1932 PatentedNov. 8, 1932' gum-ran STATES LILoYn A. rurrnn, or ,cnroes nnnvors,ASSIGNOR 'ro onrcneo MAmronn rnonuorsi COMPANY, or CHIOAGQ'ILLINOIS,Aramnnnsmr coMrosn'n or LLOYD'A. Terran ::r

Lam DAVID E. JONES. I

nuPLI'cATrnG- mcninn Application filed February 26, 1932. jSerial No..595,290.

My invention 1 relates to duplicating ma chines which print fromtypean'd comprise a rotary printing drum having a series ofundercut'channels in its periphery, extending parallel with its axis toreceive type which the drum presents in opposition to an impressionplaten comprising the other member of the printing -couple. Asordinarily accomplished, the printedimpressions from such a machine areirregular when the lines of'type are less than'full length, the typeprinting more heavily in such instances, because the pressure isvariable per unitof length for each line; and the invention has for itsmain object to provide a simple adjjunct for equalizing the printingpressure, whereby the short lines are printed no darker than the linesof full length.

A further object of the invention is to mount the novel equalizing unitbeyondthe type bearing area of the printing drum, whereby to present nointerference to the type or access thereto. i

A still further object of the/invention is to-make the novelequalizing-unit quickly attachable upon or removable from the printingdrum, and of a nature tobe interchangeable relative to standard typeprinting drums.

Another object of the invention is to construct the novel equalizingunit with means for the handy and easy applicationof equalizing elementsopposite any line oftype.

-An additional object of the invention is to build theimpression platenup with a reinforcement opposite the equalizing unit, whereby to presenta firm surface ofcontact yet preserve the resiliency of the impression.A final but nevertheless important object of the invention is to designthe novel equalizing unit on lines of durability andutmost simplicity.

With the above objects in View and any others that may suggestthemselves from the specification and claims to follow, abetterunderstanding of the invention may be had by reference totheaccompanying drawing, in which- 7 p Fig. l isan end view of a typicalduplicating machine showing the application of'the novel equalizingunit;

Fig.2: is an enlarged and inverted cross section; of a fragment of theprintingdrum showing the position-of the equalizing unit;

. Figs. 3 and 4: are.fragmentaryend-vieWS of the inverted drum,representing the lefthand and right-hand limits thereof,

Fig. 5 is a fragmental plan view of Fig. 4;

Fig.6, is a perspective view of an equalizing element; and

Fig. 7 is a fragmental section of the couple formedby'the printing drumand'the impression platen as taken on the line 7.7 of Fig. 1 and showingthe equalizing unit there-- between.

Referringspecifically to the drawing, 10

denotes the periphery of the conventionalprinting drum in machines ofthe type re ferred to, such periphery being built up with a series oflongitudinal type ribs or rails ll defining spaces 11w inwhich the typeslugs 12 are slid. 'Fig. '2 shows a View of such slugs-representingspacers and a spring retainer '13 therefor merely for purposesof'i'llustration.

Usually,the lines of type reachconsi'der-v ably short of one end of theprinting drum,

with atongue 14 so that it may behooked over the terminal drum rib 11 tosecure the corresponding end of the strap 14, as clearly shown in Fig.8. a After the strap has been closely wrapped over the drum, it isfastened at the other end by'means' of an eccentric cam 140 which itcarries on thejunder side. This cam is pivotedon a screw 14d and has alever extension 146. By reference to Figs. 4: and 5, it will beseen'that'the lever 14 has been swung to the drum whereby to draw thestrap tightly upon the drum and maintain the'same secured'thereto bythepassage of the cam 14c beyond its" center line. Of course, othermeans may be used tosewhich may for the present purpose be called Thestrap 14 is employed to form a base for the elements immediatelyaccomplishing the equalizing function. These elements are 7 in thenature of clips 15 also of spring metal and intended to be positionedtransversely upon the strap 14. Each clip 15 is a narrow.

- strip. bent down at the ends, with hooks 15a and 15b, thel'atter beingextended withan outward stem 150; also, the clips. are. built upmedially with a longitudinal rib 15d hav ing an abrupt bevel 156 at oneside and gradual bevel 15f at the other side, these bevels meeting theside edges of the clip-15.

.A supply of the clips 15-goes with each strap 14, and any clip may be.mounted upon the strap to assume the position shown in Fig. 2. This isdone by undercutting the strap 14 at both side edges in themannerindicated at 114, then engagingthe hook 15a of the clip at the front,and finally, pressing the clip down to engage the. hook 157) at therear, F or equalizing purposes, each clip must occupy a positiondirectly opposite the type groove 11a, as clearly shown in Fig. 5 andthe clips are therefore only so-wide as to permit the successivegrouping thereof if desired line after line. Also, the stem 15a of anyclip is sufiiciently narrow to enter the groove 11a when the clip ispressed in place, so that the clip is locked in the position set andcannot depart from the line represented by the groove 11a. However, theclip may be removed by the application of a small pryingtool, ifdesired. Fig.7 shows the position of the strap 14 as carried bytheprinting drum 10 in opposition to the impressionplaten 16 of .themachine. It will be ,noted that thisplaten is mounted with a rubberjacket 16a, this jacket having a slight amount of resiliency. Inasmuchasthe clips 15 must come into rolling contact with the periphery of thejacket 160; during the action of the drum and platen, and with somepressure where the spaces representing the short lines of type occur, itmust follow that the ribs 15cZ'would impress and soon damage the jacketof the platen. I have therefore reinforced the jacket with a metal band17, preferably cutting the jacket down sufficiently to permit the bandto be pressed on firmly and be disposed flush with the periphery of thejacket. r

In the operation of the novel equalizing unit, it will be apparent thata clip 15 s provided for each short line of type. Owing to the fact thatthe printing pressure varies with the length of the short line spaces, Iform the ribs 15d with a height or prominence to correspond. Thus, wherethe line of type is fairly long, the rib is quite low; and where theline is short the rib is perceptibly higher. Obviously, an assortmentmy'intention that their efiect confine itself immediately to thezone ofnecessity and not. that beyond... This. zone may be designated as theparticular line of type whose pressure is to be equalized, and theequalizing element must not extend its easing effect to the next .fullline in either direction, as that line will be forced to print toolightly. To this end, I have constructed the. clip ribs115cl with thebevels 15e-and 15f aforesaid." The bevel 15c occurs on the advancingside of the clip, andtherefore gives the latter an'early start torelieve theshort line pressure. However, the bevel 15f'is on the leavingside ofv theclip and permits the short line pressure to be grade uallyrelieved whereby to smoothly yet fully occasion the normal full linepressure for the next line in printing order.

It will be seen that'the novel unit is a simple attachment which maybeeasily applied or removed in connection with the standard printing drum.It is outside ofthe zone of the type-or devices to clamp the latter,-andis easily accessible. Also, its combination with the reinforced pressureplaten assures the firm rollingcontact of the strap and its equalizingelements while taking advantage of the resiliency of the pressureplaten.

I claim i 1. An equalizing unit for duplicating ma-. chine drums havinga plurality'of spaced type ribs-on the periphery thereof, said unitcomprising means mountable upon said typeribs adjacent one end of thedrum. periphery, and type-pressure equalizing elements applicable tosaid means. 1

2. An vequalizing unit for duplicatingmachine drums havinga plurality oftype ribs on the periphery thereof,saidunit comprising means mountableupon said type ribs adj acent. one endof the drum periphery,andtypepressure equalizing elements applicable to said meansat selectedpoints intermediate adjacent type ribs." 7

3. Anequalizing unit for duplicating machine drums comprising a strapwrapped over one end of the-drum periphery, clips mounted transverselyupon the strap, and raised surface portions on" the clips.

4. The structure of claim 3, said portions being ribs.

'5'. The structure of claim '3, said portions being ribs extendinglongitudinally ofthe drum. I a r Y -6. The structure of claim 3, saidportions being ribsextending longitudinally of the equalizing j aredrum, and of various heights dependent on the extent of equalizationnecessary.

7. The structure of claim 3, said portions being ribs. extendinglongitudinally of the drum, and whose sides bevel down to the side edgesof the clip.

8. The structure of claim 3, said portions being ribs extendinglongitudinally of the. drum, and whose sides bevel down to the sideedges of the clip, and the bevels differing radically in slope.

9. An equalizing unit for duplicating machine drums comprising a strapwrapped over one end of the drum periphery, the side edges of the strapbeing undercut, and clips mounted transversely upon the strap, the endportions of the clips being bent to form hooks engaging saidundercutedges.

10. An equalizing unit for duplicating machine drums comprising a strapwrapped over one end of the drum periphery, the side edges of the strapbeing undercut, and clips mounted transversely upon the strap, the endportions of the clips being bent to form hooks engaging said undercutedges, and of spring material to grip them with tension.

11. An equalizing unit for duplicating ma chine drums having a pluralityof type ribs on the periphery thereof, said unit comprising meansmountable at one end of the drum periphery, type-pressure equalizingelements applicable to said means, said means comprising a strap Wrappedover the drum periphery and having type rib engaging means at each endthereof.

12. An equalizing unit for duplicating machine drums having a pluralityof type ribs on the periphery thereof, said unit comprising meansmountable at one end of the drum I periphery, type-pressure equalizingelements applicable to said means, said means comprising a strap wrappedover the drum periphery, and type rib engaging devices endwise of thestrap to secure the same in position, one of said devices being a hook,and the other a mechanism to draw the strap tight.

13. An equalizing unit for duplicating machine drums, comprising meansmountable at one end of the drum periphery, type-pressure equalizingelements applicable to said means, said means comprising a strap wrappedover the drum periphery, and devices endwise of the strap to secure thesame to the transverse end portions of the drum, one of said devicesbeing a hook, and the other an eccentric cam operable to draw the straptight.

14. An equalizing unit for duplicating machine drums and the cushionedimpression platens co-operative therewith, comprising means mountable onthe drum periphery, type-pressure equalizing elements projected from thesurface of such means, and aperipheral reinforcement for said impressionplaten and disposed forrolling contact with said elements.

15. An equalizing unit for duplicating machine drums and the cushionedimpression platens co-operative therewith, comprising means mountable'on the drum periphery, type-pressure equalizing elements projected fromthe surfaceof such means, and a band of hard materialcarried'peripherally by the impression platen and positioned for rollingcontact with said elements.

16. An equalizing unit for duplicating machine drums having a pluralityof s aced type ribs on the periphery thereof de ning type line groovestherebetween, said unit comprising means mountable upon said ribsadjacent one end thereof and type pressure equalizing elementsapplicable to said means at selected points in line with said grooves,said elements having extensions adapted to project into said grooves toretain said elements against displacement transversely of said grooves.

17. An equalizing unit for duplicating machine drums having type ribsupon the periphery thereof, said unit comprising'a strap wrapped overthe periphery of said drum and extending across said ribs, and typepressure equalizing elements in the form of raised clips applicable tosaid strap at selected points intermediate the ends thereof andextending transversely thereof.

In testimony whereof I affix my signature. I LLOYD A. TUPPER.

